The present invention claims priority to U.S. Provisional Application No. 60/695,390 filed Jun. 30, 2005 entitled “Information for Connecting VLSI Design and Manufacturing/Critical Net Extraction for VLSI Design and Manufacturing”.
The present invention relates generally to an integrated circuit (IC) design, and more particularly to a method for optimally converting a circuit design into a semiconductor device.
New IC creation is an extremely time-consuming, labor-intensive, and costly endeavor. The IC creation process can be divided into the IC design/verification stage and the IC fabrication/test stage. The circuit design houses produce circuit designs according to certain predefined specifications. The semiconductor foundries then receive the circuit designs from the design houses and convert them into semiconductor devices using their proprietary intellectual properties or technical library. The circuit design houses include, for example, fabless companies and circuit design organization of integrated device manufacturers (IDMs). The fabless companies do not have their own company plants to manufacture their ICs design, while the IDMs have their own company plants. The IDMs may manufacture their IC designs within their own company plants or through outside pure semiconductor foundry house. The fabless companies have to entrust the pure semiconductor foundry houses with their IC designs for manufacturing semiconductor devices.
While a circuit design may include various kinds of components connected by a plurality of conductive lines, not all of the components are of equal importance. For example, a device may be placed in an area where the accuracy of signal timing is crucial to the entire circuit, whereas another device may be placed in an area that requires less accurate signal timing. Traditionally, the design information received by the foundry from the design house does not differentiate the crucial components from the non-crucial ones. As such, the foundry applies the same set of fabrication conditions in manufacturing comparable parts of the crucial and non-crucial components.
One drawback of the conventional approach to converting the circuit design into the semiconductor device is its inefficiency. Conventionally, both the crucial and non-crucial portions of the circuit design are manufactured using the same fabrication conditions. On the one hand, such fabrication conditions may not be able to provide the crucial portion implemented in the semiconductor device with desired electronic characteristics. On the other hand, they may waste valuable resources in fabricating the non-crucial portion, which has a relatively low quality requirement. The conventional approach is not an optimal method for converting the circuit design into the semiconductor, thereby rendering the conversion inefficient.
Thus, it is desirable to devise new methods for optimizing the process of converting the circuit design into the semiconductor device.